In Leonard/Sheldon's apartment the gang, minus Sheldon and Howard, are having dinner. Raj is sitting in Sheldon's Spot and is not worried about him finding out. Leonard remarks that Sheldon has an extremely sensitive posterior and once sat on some spare change and added it up. Sheldon was so good at Howard’s lecture that he bought him a Buzz Aldrinbobble-headdoll. Stuart enters the apartment while they are trying to decide what to do that night. Bernadette begs them to find something to do since she promised Howard she would look in after his mother if they had nothing to do. Raj is excited that they can do whatever they want since Sheldon is gone, so they ordered Thai food from a different restaurant that turned out to be terrible. Stuart eats some food, looks terrible and drops to the floor. While everyone tries to help him, Raj announces that it is too late and that he has been murdered by someone in the apartment. Raj is having a murder mystery night. Everybody moans and Amy gets ready to leave. Bernadette never realized that Stuart’s last name was Bloom.

Standing around Stuart, Penny is worried that Raj wants them to pretend to be a bunch of lame characters with silly accents. Raj then asks her what kind of an actress she is, so she remarks how much “fun” this game is going to be. That’s the kind of actress she is. Raj has them playing themselves though Amy wanted to be somebody else. He hands out envelopes which contain facts about their character including who was the murderer. The game is to ask each other questions and to look for clues. Penny asks who is the murderer which is an illegal question to ask. Then she reverses it and asks who is not the murderer.

Who killed Stuart Bloom?

In Houston, Sheldon is enjoying his new astronaut bobble-head, while Howard is driving them to his mother’s house. Sheldon found it hard to not make comments during Howard’s lecture at NASA. Howard thinks that they have to show up with something. Sheldon is bringing the gift of knowledge. Fact: Though referenced in his mother’s bible, camels did not exist in the holy land until hundreds of years later. Howard quips that he thought they would get a cake or a pie, but an insult is always thoughtful.

During the murder mystery night, Raj has hidden clues around the apartment. Penny is going to search the refrigerator for any hidden in a beer. Amy finds a little figurine carrying briefcase, but that is from the game that Sheldon invented, Chutes and Lawyers. Raj reminisces that back in India he was a heavy child and had to make up stories to entertain himself, so as an adult he is trying to do the same thing with his friends. Leonard has seen pictures of him as a child and he was not heavy. Raj then notes that he is great at telling stories. Bernadette finds a receipt for coffee dated twentyyears in the future. Somebody in the room came from the future to murder Stuart which sounds just like the movie "The Terminator". As Leonard and Raj argue over the source of that moviescript, Penny goes back to the refrigerator to get another clue.

Arriving at his mother's house, Sheldon wants to carry on the flowers and pie even though Howard bought them. Sheldon still felt that his very presence was enough of a gift. He can wait to see his mother’s expression, peeks in the front room window and runs back into the car. He wants to leave because he saw his mother

At a neighborhood bar and Howard and Sheldon are each having a beer. Sheldon isn’t drunk enough yet to discuss what happened with Howard so he takes one sip and is then ready. Howard has never had that experienced, but has seen his mother ravishing a brisket. First Howard suggests that he doesn't tell her and then he discourages him from just calling her. Then Howard points out that this Mom is a grown woman and his father has been gone a long time and maybe what went on is none of his business. Sheldon feels that since he once occupied that space, he should have a say into who moves into his old room.

In the game, Raj takes the gang to twenty years in the future, though his friends show no real interest. Penny finds that her beer is not flat and her rack is not saggy, so she is happy. Raj hands out his facts about the gang’s future selves. Amy won a Nobel Prize, bought Stuart's comic book store and closed it so Sheldon would pay more attention to her. She is happy about that future. Penny is a famous actress in London, while Leonard is a professor at Stanford University in California and they have drifted apart. Raj also drifted away from them after he married Madonna. Leonard and Penny then wondered that they would do if they became famous. Penny is convinced that Leonard will be following his famous actress wife around because they won’t need the money. Raj changes their back-story to the both live in New York and have three beautiful kids. Penny then objects to putting her body through three pregnancies.

Back at Mary Cooper's house, Howard lets Sheldon face his mother by himself to face he about her sex life. Mary Cooper is very happy to see her son until he immediately mentions what he saw. She apologizes. Sheldon doesn't want to sit in a chair that they had had coitus in, so they sit at the dining roomtable. Sheldon finds out that his mother met her boyfriend Ron at a prayer meeting and that they had been involved for a few months. Then he wants to know how long she had been a demented sex pervert. Even though that was no way to talk to his mother, he found her a hypocrite after quoting the bible his entire childhood. Mary Cooper gives him on chance to apologize and then sends him to his old room despite him being a professionalscientist, a grown man and occupying the moralhigh ground.

The gang continues their discussion about Leonard and Penny. Leonard doesn’t understand why Penny’s career is more important. The other girls are surprised they never talked about their future together. Amy and Sheldon’s Relationship Agreement covers careers, finances and intelligentdog uprisings. Penny has no idea what will happen in twenty years. Stuart thinks that Penny and Leonard will be together because have a solid relationship. Penny thanks him and is sorry that she murdered him prematurely ending the game to the relief of the others.

In Sheldon's bedroom, he is playing with his Lego and Howard comes in to talk. Sheldon lets him come in since any man is welcomed in. Howard starts to describe a similar situation and Sheldon cuts him off that they have all seen his mother naked because she never ties up her robe. After Howard's father left them, his mother started seeing a guy who Howard drove away after delivering a vicious attack during his Bar Mitzvah speech leaving his mother all alone. Howard doesn't want him to do the same thing to his mother. Sheldon concedes his point since he loves his mother even if she does fornicate like a demonicweasel.

Sheldon goes down to see his mother who what to talk calmly like adults. She is sitting on the couch and does cover a spot so that Sheldon will sit on it. Mary Cooper again apologizes for what he saw. Sheldon again objects to the hypocrisy after all the religiousphilosophy she has been promoting her entire life. His mother says that she has been struggling with her beliefs. She is not perfect, but she does find Ron’s rear is. Though Sheldon finds it confusing, he plans on condemning her internally with an outward appearance of acceptance. Mary Cooper tells her son that that is very Christian of him. Sheldon then tells her that the world has change since she was young. It’s no longer sock hops, soda jerks and segregation. Mary wonders how old Sheldon thinks she is. Sheldon wants to make sure she is careful and uses latex. Mary looks to the Lord since Sheldon is trying to have the sex talk with her.

Mary Cooper sending her son to his old room.

While cleaning up dinner, Raj is brooding over how his game ended. Bernadette did like the time travel element. Raj thought that it was inspired. Leonard added that it was inspired by "The Terminator". The gang is wondering if they will all be friends twenty years from now and agree to meet there in twenty years and have dinner together. Everyone enters the date in their phone except Stuart who writes it on his hand. Flash ahead twenty years and only Stuart shows up in front of the apartment building for the planned dinner.

Jesse Schedeen of IGN - The good news is that the murder mystery itself was little more than window dressing...(Stuart's) comment that Leonard and Penny are the best couple he knows because they make each other better was surprisingly profound for the typically downtrodden comic shop owner. And it illustrates why, despite all the us and downs the duo have faced over the years, their relationship is very much the heart and soul of the series...It was a very different confrontation between Sheldon and his mother from the last time he wrestled with the notion of a man in her life, but it was definitely funny...Ultimately, both Coopers experienced some welcome character growth. Mary acknowledged that she isn't perfect, even if her boyfriend's booty is. And Sheldon realized that it's better to accept that his mother is an adult woman with needs and desires, lest he give rise to another Mrs. Wolowitz. The horror...

Second episode where Raj organizes an activity for the gang which causes conflict for Leonard and Penny; the first was "The Scavenger Vortex".

The gang were mentioned to have kept blowing off Raj's Murder Mystery parties in "The Scavenger Vortex".

Stuart is involved in the Murder Mystery party after complaining about not being included in the scavenger hunt in "The Scavenger Vortex".

Bernadette's competitive nature is again shown in this episode, which was first shown in "The Scavenger Vortex".

First appearance of Leonard wearing a shirt instead of a hoodie and a jacket.

First time Mary has appeared in more than one episode of a season.

Sheldon and Howard do not share any scenes with the rest of the gang in this episode.

Crisis on Infinite Earths #8

On the wall in Sheldon's childhood bedroom at Mary Cooper's house, we see a poster of the cover for Crisis on Infinite Earths #8; the November 1985 issue featuring the death of Barry Allen, the Silver-age Flash.

Howard recalls when his mother was dating a man shortly after his father left and how much he resented it. However, surprisingly he doesn't mention accidentally coming home to catch her in a compromising position with his dentist ("The Re-Entry Minimization"), though this situation was both fairly recent and closely mirrors Sheldon's own dilemma.

Bernadette makes a comment and Raj calls her a regular Byomkesh Bakshi. Bernadette wonders if that is an Indian Sherlock Holmes. Raj retorts that maybe Sherlock Holmes the English Byomkesh Bakshi. Amy checks and announces that Sherlock Holmes came first, where Raj mumbles that everyone has to be a Byomkesh Bakshi.

Raj: Sheldon is out of town so we can whatever we want. We even ordered from the Thai place he doesn't like.

Stuart: How is it?

Penny: Disgusting. Do not tell him.

Leonard: What do you guys want to do tonight?

Amy: I don’t know.

Bernadette: I told Howie if I wasn't busy I’d spend the night at his Mom’s. So for God sakes, think of something.

Raj: Welcome to another classic Koothrappali murder mystery dinner.

Amy: I’m leaving.

Penny: Are you going to make us pretend to be a bunch of lame characters with silly accents?

Raj: Lame characters with silly acc--What kind of an actress are you?

Leonard: Does the gazelle with a flair for storytelling know that he’s just ripping off Terminator?

Raj: Does the smart-ass know that Terminator was actually ripped off from an Outer Limits script called Demon with a Glass Hand by Harlan Ellison?

Leonard: Oh, does the gazelle know that according to Harlan Ellison, it was not ripped off from Demon with a Glass Hand, but was ripped off from another Outer Limits script he wrote called the Soldier?

Penny: I'm gonna need another clue!

Sheldon: Boy, I can’t wait to see the look on her face..... We’re leaving right now.

Howard: What's wrong?

Sheldon: Nothing.

Howard: What? Sheldon, tell me what's going on!

Sheldon: I saw my mommy with a naked man and she’s trying to be a mommy again.

Stuart: Well, I feel like you guys make each other better. Penny brought Leonard out of your shell. Seems like Leonard makes Penny think more deeply about the world. I don’t know. Together you two make one awesome person.

Penny: Aw, Stuart. Now I feel bad for murdering you.

Raj: Oh, come on!

Bernadette: Penny did it! I win! Suck it, jackasses!

Howard: All I'm saying is you might not want to get in the way of your mom’s happiness.

Sheldon: I love my mother. Even if she fornicates like a demonic weasel.

Sheldon: I think what bothers me the most is the hypocrisy. Doesn't this contradict all the religious rules you've been espousing your whole life?

Mary Cooper: You're right, it does. And it's something that I'm struggling with these days.

Sheldon: Then, why are you doing it?

Mary Cooper: Because I’m not perfect, Shelly, and that man’s booty is.

Sheldon: Well, this is confusing for me. But I don’t want to stand in the way of your happiness. So I’ll condemn you internally while maintaining an outward appearance of acceptance.